| Kenmar Tek AS | Information & communication | 2019 |
| Kensjø AS | Professional & scientific | 2020 |
| Kenzo Invest AS | Health & social care | 2018 |
| Keralight AS | Professional & scientific | 2019 |
| Kero Invest AS | | 2016 |
| Keta Invest AS | Professional & scientific | 2007 |
| Keto Bygg AS | Real estate | 2015 |
| KG Aukan Holding AS | | 2022 |
| KGL AS | Financial services | 2012 |
| KGT 35 AS | Real estate | 2015 |
| Khine AS | Real estate | 2021 |
| Khjem AS | Administrative & support | 2023 |
| KHL Holding AS | Professional & scientific | 2013 |
| Kibsgård Bygg AS | Construction | 2013 |
| Kibsgård Holding AS | | 2026 |
| Kibu AS | Professional & scientific | 2007 |
| Kick-Ass AS | Hospitality | 2017 |
| Kiilgården AS | Real estate | 2018 |
| Kikimora Arkitekter AS | Professional & scientific | 1982 |
| Kikkertspesialisten AS | Wholesale & retail | 1994 |
| Kilden Invest AS | | 2021 |
| Kili AS | Real estate | 2016 |
| Kilimanjaro AS | Hospitality | 2024 |
| Kimmen AS | Financial services | 2017 |
| Kina Kjøkken AS | Hospitality | 2020 |
| Kine Aasen Holding AS | | 2025 |
| Kines Renhold AS | Administrative & support | 2015 |
| Kingsinvest AS | Real estate | 2000 |
| Kinonor AS | Information & communication | 2014 |
| Kiona AS | Information & communication | 2002 |
| Kiona Holding AS | Information & communication | 2001 |
| Kioskdrift Børseth AS | Wholesale & retail | 2024 |
| Kioskdrift Masai Akbari AS | Wholesale & retail | 2025 |
| Kipervikgata 34 AS | Real estate | 2025 |
| Kippervika AS | | 2025 |
| Kippi AS | Information & communication | 2026 |
| Kirkegata 17 a AS | Real estate | 2016 |
| Kirkegata 18 Trondheim AS | Real estate | 2017 |
| Kirkegata 61 a AS | Real estate | 2018 |
| Kiropraktor Bernt Schjetne AS | Health & social care | 2000 |
| Kiropraktor Glenn Angelsen AS | Health & social care | 2013 |
| Kiropraktor Kjell Georg Eilertsen AS | Health & social care | 2011 |
| Kiropraktorgården AS | Health & social care | 2019 |
| Kiropraktorklinikken God Rygg AS | Health & social care | 2004 |
| Kitt Og Sprosse Vindusverksted Ans | Manufacturing | 2000 |
| Kizu AS | Professional & scientific | 2018 |
| KJ Consulting AS | Professional & scientific | 2025 |
| Kjbak 821 Holding AS | | 2023 |
| Kje Invest AS | Real estate | 2008 |
| Kjeila AS | | 2005 |
| Kjeila Mausund AS | Real estate | 2021 |
| Kjeldsberg Bolig AS | Real estate | 2014 |
| Kjeldsberg Boligforvaltning AS | Professional & scientific | 2007 |
| Kjeldsberg Eiendom AS | Real estate | 2007 |
| Kjeldsberg Eiendomsforvaltning AS | Real estate | 1999 |
| Kjeldsberg Holding AS | Real estate | 2018 |
| Kjeldsberg Invest AS | Real estate | 2018 |
| Kjeldsberg Kaffe Eiendom AS | Real estate | 2012 |
| Kjeldsberg Kaffebrenneri AS | Manufacturing | 1952 |
| Kjeldsberg Transporttjenester AS | Transport & logistics | 2020 |
| Kjell Arne Kjeldsberg AS | Wholesale & retail | 2019 |
| Kjell Hagen A/S | Construction | 1988 |
| Kjell Ola Holding AS | | 2022 |
| Kjell Tveterås Invest AS | Financial services | 1998 |
| Kjell Ulriksen Holding AS | Real estate | 2016 |
| Kjellneset AS | Real estate | 2019 |
| Kjelsås Butikkeiendom AS | Real estate | 2025 |
| Kjelås Bil AS | Wholesale & retail | 2022 |
| Kjemiteknikk AS | | 2023 |
| Kjempehyggelig AS | Hospitality | 2018 |
| Kjempetroll AS | Hospitality | 2021 |
| Kjerneverket AS | Professional & scientific | 2025 |
| Kjersti Gah Helland Holding AS | | 2025 |
| Kjesbu Invest AS | | 2020 |
| Kjetil Bjørvik Invest AS | Real estate | 2011 |
| Kjetil Evenmo AS | Financial services | 2017 |
| Kjeveortoped Brusveen AS | Health & social care | 2021 |
| Kjeveortoped Holstad AS | Health & social care | 2026 |
| Kjeveortoped Lars Aursand AS | Health & social care | 2006 |
| Kjeveortoped Vegard B. Vårum AS | Health & social care | 2026 |
| Kjopmannsgata 31 AS | Real estate | 2024 |
| KJR AS | Professional & scientific | 2009 |
| Kjærnsmo Automatservice AS | Administrative & support | 2018 |
| Kjøkkenspesialisten AS | Wholesale & retail | 2017 |
| Kjøleutleie AS | Administrative & support | 2025 |
| Kjølhamar AS | | 2018 |
| Kjøpmannsbrygga Da | Real estate | 2022 |
| Kjøpmannsgata 10 AS | | 2026 |
| Kjøpmannsgata 17 AS | Real estate | 2023 |
| Kjøpmannsgata 19 AS | Real estate | 2002 |
| Kjøpmannsgata 33 AS | Real estate | 2021 |
| Kjøpmannsgata 34 AS | Real estate | 2025 |
| Kjøpmannsgata 36/38 AS | Real estate | 2018 |
| Kjøpmannsgata 5 AS | Real estate | 2006 |
| Kjøpmannsgata 50 AS | Real estate | 2024 |
| Kjøpmannsgata 52 AS | Real estate | 2006 |
| Kjøpmannsgata 7 Trondheim AS | Real estate | 2013 |
| Kjøpmannsgata Ung Kunst AS | Wholesale & retail | 2006 |
| Kjøpmannsgaten 6 AS | Real estate | 1962 |
| Kjøpmannsgt 40 Da | Real estate | 1997 |